How belly bugs can provide insight into the disease

Have you thought about your gut bugs lately? Belly bacteria is front and center in many of the latest scientific breakthroughs; researchers have found links between the bacteria that lines the colon and so many health conditions, from obesity to asthma. (Check out our feature on what gut bacteria can reveal about your health here.)

But it doesn’t stop there: a new study from Arizona State University has discovered a link between gut bacteria and autism.

In the study published in the journal PLoS ONE, researchers checked out the populations of healthy gut bugs in 40 kids between the ages of 3 and 16, half with autism and half without. After sequencing bacterial DNA in stool samples from the participants, researchers found that autistic subjects had less diverse gut microbes than their neurotypical peers.

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That’s important, because a more diverse gut is a healthier one—the more kinds of microbes you have, the more resistant they are to pathogens. (It’s perhaps no surprise, then, that kids with autism often have GI problems.) But intriguingly, the team found that autism itself, rather than the GI symptoms with which autism is often paired, was associated with the lower diversity.

The microorganisms in autistic kids’ bellies might be responsible for much more than just their GI problems, though the implications are unclear at this point. But researchers were able to determine exactly which types of microorganisms were lacking in autistic kids. They’re deficient in healthy fermenters, like Prevotella, that help break down carbohydrates. “It could be that these fermenters produce some other metabolites that are important for GI health or neurotransmission,” said Rosa Krajmalnik-Brown, PhD, assistant professor at Arizona State University’s Biodesign Institute and one of the study’s authors.

It’s one of the first studies to look at beneficial bacteria, as opposed to pathogens, in kids with autism. “If they’re missing good guys, that’s actually a step further in treatment,” Dr. Krajmalnik-Brown explained. “It’s easier to add it—a probiotic approach.”

Prevotella probiotic pills are a ways off—and there’s no telling if they’d even work—but research like this shows a promising gut/mental health connection. “It really opens a lot of other possibilities for healing other diseases, not just the disorder of autism,” Dr. Krajmalnik-Brown said. “Right now, I don’t have the secret recipe yet, but I, and many other scientists, are working on it.”